1. Technical Field
This disclosure relates a process for producing high fructose corn syrup (HFCS), in which a mixed feed solution of glucose and fructose is obtained from the isomerization tower. It employs as a subsequent unit operation for separating opponents of sugar mixture. More boldly, this process is used for the continuous separation of the glucose and fructose solution mixtures to retrieve various grades of glucose and fructose solution mixture and to elevate the concentration level of the separated fraction. Yet, when this process compares with traditional chromatographic process. It has its ultimate object to consume much less resin inventory and eluent water to gain the ultimate purity and higher concentration of glucose and fructose component with ultimate yield and lower production cost.
2. The Description of Prior Art
It is known that the process currently been used for separating the solution mixtures of glucose and fructose is by inputting the feed solution through a cation exchange chromatographic column then by introducing the de-ionized water to elute the dissolved components through which the separation is obtained. As taught by U.S. Pat. No. 3,044,904, U.S. Pat. No. 4,472,203, U.S. Pat. No. 4,395,292, Japanese Pat. No. 24,807 of 1970, and many other unlisted disclosures, without exception, single fixed bed chromatography is the basic mechanical device along with resembling mass transfer mechanism been used in those publications. The separation is carried out within a typical long and tall column packed with stationary resin. They are all fallen into some category of mass transfer phenomena that occurs within so called the mass transfer zone in which the eluent water is in conjunction with feed. As such zone is being transported by continuous introducing the eluent water pushing behind the feed solution, the fructose is retained by the resin to a greater degree than glucose through which the separation is achieved. At any instance of chromatographic operation, the contributed resin for separation is only when such zone passed by and the remaining are idle. Note that the so-called the displacement zone is always existed as eluent water pushing off previous feed introducing through resin bed to proceed separation. As various methods and processes being developed upon said mass transfer mechanism in chromatography, the column process has been long recognized and implemented as standard equipment that inherent with shortcomings. Such fundamental mass transfer mechanism has not been further improved through using same resin and eluent in much less inventory and yet gaining better separation. Those imperfections are multifaceted coexisted and affecting one another, which are briefly illustrated as following:
Inefficient usage of resin, the mass transfer proceeded only at the very front of mass transfer zone, the resin before and after such zone are idle; PA1 Due to exist of displacement zone to create excess dilution and to increase cycle time thus enhancing inefficient usage of resin; PA1 Engineering drawbacks of column process; listed as following; PA1 Require long cycle time to further weaken economic consumption of resin and eluent, to intensify said engineering drawbacks; and PA1 Require long cycle time to further weaken economic consumption of resin and eluent, to intensify said engineering drawback; and PA1 High-pressure drop and difficulty in maintenance. PA1 1. Retain solid phase material in a cell having an inlet on one side and an outlet on another size with bottom meshed filter to contain said material from being drained. PA1 2. Intermittently deliver predetermined amounts of liquid material to either promoting adsorption of dissolved components onto said material or solution of adsorbed components from said material. PA1 3. Intermittenly supply pressurized gas to the cell on the one side following each delivery of a liquid to force prompt draining of delivered liquid said material to complete expected mass transfer between two phases. PA1 4. Maintain a vacuum on the other side of said material to maintain said material is semi-fry status. PA1 5. Intermittenly collecting most of treated solution from the outlet of cell. PA1 6. Total time spent from 2 to step 5 is defined as minimal time interval.
1. Flow dynamics: axial dispersion and diffusion effects are important in affecting separation quality, include back mixing of column and effects. PA2 2. Column geometry: in and out, column end-effects includes dead volume. PA2 3. Loading limitation: to avoid peak broadening, overlapping and tailing due flow-dynamics.
An improved simulated moving bed process, abbreviated as SMB, is taught in both Japanese Provisional Patent Publication No. 26336 of 1978 in which zeolite is used as resin and Japanese Provisional Patent Publication No. 88355 of 1978 in which a cation exchange resin is used. In those later becomes well accepted as industrial process for glucose and fructose separation. The process compromises multiple columns connected in series, each column has its distributors to allow fluid to flow into and out of such column. Actually, each column in such series connection represents a particular mass-transfer task compared to a long column to carry out all tasks in sequence. At a setting time interval, all points of feed loading, eluent introducing, product and by-product withdrawals are shifted simultaneously purposely for cutting down resin consumption. Unlike rapid virtue of high ion mobility and electrical actions in water ion exchange reactions, the glucose and fructose separations are very slow. These sugars are non-electrolytes and their separation is governed by a very narrow difference interaction between sugar components and resin. An additional factor in affecting such interaction difference is water content within the mobile phase, it eliminates such interaction to minimal when too much water exists due sugars are very soluble in water. Despite various difficult natures, the general practice of SMB process operates at a flow rate of 0.8 to 1.0 bed-volume per hour for achieving separation based on small interaction difference between sugar components and resin. In the other words, the process takes 1 to 1.25 hours to complete a separation cycle. Nevertheleess, the loading limitation is set at 0.05 to 0.1 feed rate to resin bed volume ratio as the operating guideline to obtain acceptable separation quality versus operation efficiency. For example, a feed input rate of 200 balloons per minute will consume 2000 balloons of resin per minute based on 0.1 ratio. For a 1 to 1.25 hours cycle process, it will consume 120,000 to 150,000 gallons of resin. In viewpoints of excess resin being used in chromatographic process, excess eluent has to be coped in order to push off the separated fractions. It surprisingly consumes about two times of eluent water as feed input rate. Overall speaking, the SMB process is far superior to a single fixed bed process in aspects of resin consumption, operation efficiency, product yield and quality. Therefore, it has been overwhelmingly adopted as the standard industrial process ever since first introduced. However, this process is limited by using chromatography with attempting in manipulating the column configuration and optimized in fluid distribution, in which the process yet inherits the aforementioned native drawbacks of column operation.